JP7811201B2 - Curable resin composition, cured product, and adhesive - Google Patents

Description

The present invention relates to a curable resin composition, and more particularly to a curable resin composition containing a cyanate ester resin, an epoxy resin, a latent curing agent, and an ion scavenger.

Epoxy resins are widely used industrially as paints, adhesives, various molding materials, etc.

Furthermore, in cases where existing epoxy resins, either used alone or in combination, do not provide sufficient properties such as curing speed or heat resistance, cyanate-epoxy composite resin compositions, which are made by mixing epoxy resins with cyanate ester resins, have come to be widely used as useful materials with fast curing and high heat resistance (see, for example, Patent Documents 1 to 5).

On the other hand, Patent Document 6 and the like disclose resin compositions containing ion scavengers, but do not disclose their use in cyanate-epoxy composite resin compositions.
Patent Document 7 describes an insulating adhesive obtained by combining an epoxy resin, a cyanate ester-based curing agent, and an inorganic ion exchange agent, but does not suggest the use of an amine-based latent curing agent containing active hydrogen in combination.

U.S. Patent No. 6,469,074 Japanese Patent Application Publication No. 60-250026 U.S. Patent No. 6,342,577 US Patent Application Publication No. 2012/178853 US Patent Application Publication No. 2012/309923 US Patent Application Publication No. 2019/031790 Japanese Patent Application Laid-Open No. 2017-103332

Cured products of the cyanate-epoxy resin compositions described in Patent Documents 1 to 5 may become cloudy under high-temperature and high-humidity conditions, which is particularly problematic when the cyanate-epoxy resin composition is used as an adhesive for optical components such as lenses.
Patent Documents 6 and 7 do not take anti-fogging properties into consideration. In particular, as described in Patent Document 7, a curing system that uses an epoxy resin and a cyanate ester-based curing agent without an amine-based latent curing agent containing active hydrogen is insufficient in curability and requires curing at high temperatures, making it unsuitable for applications such as adhesives.

Therefore, the problem that the present invention aims to solve is to provide a curable resin composition that has excellent curing properties and produces a cured product that has excellent anti-fogging properties even when placed under high temperature and high humidity conditions.

After extensive research, the inventors discovered that a curable resin composition containing a cyanate ester resin, an epoxy resin, an amine-based latent curing agent containing active hydrogen, and an ion scavenger can achieve the above-mentioned objective, and thus arrived at the present invention.

That is, the present invention provides a curable resin composition containing (A) a cyanate ester resin, (B) an epoxy resin, (C) an amine-based latent curing agent containing active hydrogen, and (D) an ion scavenger.

The present invention also provides a cured product of the curable resin composition and an adhesive containing the curable resin composition.

The curable resin composition of the present invention will be described below.
The present inventors speculated that the cause of cloudiness in cyanate-epoxy curable resin compositions is the precipitation of components produced by the reaction of components resulting from the decomposition of adhesive components in a high-temperature, high-humidity environment with silicon, sodium, etc. derived from glass. They then considered that the components produced by the decomposition of a cured product of a cyanate-epoxy curable resin composition in a high-temperature, high-humidity environment could be captured by an ion scavenger, and arrived at the use of an ion scavenger in a specific formulation containing a cyanate-epoxy resin composition.

The cyanate ester resin, component (A) used in the present invention, is a compound having two or more cyanate groups and can be used without any particular restrictions on molecular structure, molecular weight, etc.

The cyanate ester resin, component (A), may be, for example, one or more compounds selected from the group consisting of compounds represented by the following formula (1), compounds represented by the following formula (2), and at least one polymer selected from the compounds represented by formula (1) and formula (2). The polymer referred to here is also referred to as a prepolymer.

NC-O-A ¹ -Y ¹ -A ² -O-CN (1)

(In the formula, Y ¹ represents a divalent hydrocarbon group that is unsubstituted or substituted with a fluorine atom or a cyanato group, or represents —O—, —S—, or a single bond, and A ¹ and A ² each independently represent an unsubstituted phenylene group or a phenylene group in which 1 to 4 hydrogen atoms on the ring are substituted with alkyl groups.)

(In the formula, m is an integer of 1 or more, ^Y2 and ^Y3 each independently represent -S- or a divalent hydrocarbon group that is unsubstituted or substituted with a fluorine atom or a cyanato group, and ^R1 to ^R6 each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.)

In this specification, examples of alkyl groups having 1 to 4 carbon atoms include methyl groups, ethyl groups, propyl groups, isopropyl groups, butyl groups, isobutyl groups, s-butyl groups, and t-butyl groups.

When a hydrogen atom on the ring of the phenylene group represented by A ¹ and A ² in formula (1) is substituted with an alkyl group, the alkyl group may be an alkyl group having 1 to 4 carbon atoms.

The unsubstituted or fluorine atom-substituted divalent hydrocarbon group represented by ^Y1 in formula (1) and ^Y2 and ^Y3 in formula (2) preferably includes one having 1 to 20 carbon atoms. Specifically, ^Y1 in formula (1) and ^Y2 and ^Y3 in formula (2) preferably have a structure represented by any one of the following formulae (Y-1) to (Y-9) because they are easily available.

Here, n is an integer of 4 to 12, ^R7 and ^R8 are each independently a hydrogen atom or an unsubstituted or fluorine-substituted methyl group, and * represents a bond.

Among the cyanate ester resins, preferred are bisphenol E-type cyanate ester resins, biphenyl-type, novolac phenol-type, and bisphenol A-type cyanate ester resins because they can provide cured products with excellent heat resistance. Examples of bisphenol-type cyanate ester resins, such as bisphenol E-type and bisphenol A-type, include resins in which ^Y1 is represented by (Y-1) in the formula (1). Examples of biphenyl-type cyanate ester resins include resins in which ^Y1 is a single bond in the formula (1). Examples of novolac phenol-type cyanate ester resins include resins in which ^Y2 and ^Y3 are each independently (Y-1) in the formula (2).

From the viewpoint of heat resistance, when a bisphenol-, biphenyl-, or novolac phenol-type cyanate ester resin is used, the bisphenol-, biphenyl-, or novolac phenol-type cyanate ester resin preferably accounts for 80% by mass or more of the total cyanate ester resin, and more preferably for 90% by mass or more of the total cyanate ester resin. In particular, in the present invention, the bisphenol-type cyanate ester resin preferably accounts for 80% by mass or more of the total cyanate ester resin, more preferably for 90% by mass or more of the bisphenol-type cyanate ester resin, and particularly preferably for 95% by mass or more of the bisphenol-type cyanate ester resin.

From the viewpoint of the balance between curability and storage stability, the content of the cyanate ester resin is preferably 5 to 80 parts by mass, and particularly preferably 10 to 60 parts by mass, per 100 parts by mass of the solid content of the composition. The solid content refers to the total amount of all components other than the solvent. The curable resin composition may or may not contain a solvent. If a solvent is contained, its content is preferably 5% by mass or less, and more preferably 2% by mass or less, of the curable resin composition.

The epoxy resin (B) used in this invention has at least two epoxy groups in the molecule and can be used without any particular restrictions on molecular structure, molecular weight, etc.

The epoxy resins include polyglycidyl ether compounds of mononuclear polyhydric phenol compounds such as hydroquinone, resorcinol, pyrocatechol, and phloroglucinol; dihydroxynaphthalene, biphenol, methylene bisphenol (bisphenol F), methylene bis(ortho-cresol), ethylidene bisphenol, isopropylidene bisphenol (bisphenol A), isopropylidene bis(ortho-cresol), tetrabromobisphenol A, 1,3-bis(4-hydroxycumylbenzene), 1,4-bis(4-hydroxycumylbenzene), 1,1,3-tris(4-hydroxyphenyl)butane, 1,1,2,2-tetra(4-hydroxyphenyl)ethane, thiobisphenol, sulfobisphenol, and oxybisphenol. Polyglycidyl ether compounds of polynuclear polyhydric phenol compounds such as phenol, phenol novolac, orthocresol novolac, ethylphenol novolac, butylphenol novolac, octylphenol novolac, resorcinol novolac, and terpene phenol; and polyglycidyl ether compounds of polyhydric alcohol compounds such as ethylene glycol, propylene glycol, butylene glycol, hexanediol, polyethylene glycol, polypropylene glycol, thioglycol, dicyclopentadiene dimethanol, 2,2-bis(4-hydroxycyclohexyl)propane (hydrogenated bisphenol A), glycerin, trimethylolpropane, pentaerythritol, sorbitol, and bisphenol A-alkylene oxide adducts. glycidyl ester compounds of aliphatic, aromatic or alicyclic polybasic acids such as maleic acid, fumaric acid, itaconic acid, succinic acid, glutaric acid, suberic acid, adipic acid, azelaic acid, sebacic acid, dimer acid, trimer acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, trimesic acid, pyromellitic acid, tetrahydrophthalic acid, and endomethylenetetrahydrophthalic acid, and homopolymers or copolymers of glycidyl methacrylate; N,N-diglycidylaniline, bis(4-(N-methyl-N-glycidylamino)phenyl)methane, diglycidyl orthotoluidine, N,N-bis(2,3-epoxypropyl)-4-(2,3-epoxypropoxy)-2-methylaniline, N,N-bis(2,3-epoxypropyl)-4-(2,3-ethoxypropoxy)-2-methylaniline, Epoxy compounds having a glycidylamino group, such as N,N,N',N'-tetra(2,3-epoxypropyl)-4,4-diaminodiphenylmethane; epoxidized products of cyclic olefin compounds, such as vinylcyclohexene diepoxide, cyclopentanediene diepoxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl-6-methylcyclohexanecarboxylate, and bis(3,4-epoxy-6-methylcyclohexylmethyl)adipate; epoxidized conjugated diene polymers, such as epoxidized polybutadiene and epoxidized styrene-butadiene copolymer; and heterocyclic compounds, such as triglycidyl isocyanurate. These epoxy resins may also be internally crosslinked with a terminal isocyanate prepolymer or polymerized with a polyvalent active hydrogen compound (such as a polyhydric phenol, a polyamine, a carbonyl group-containing compound, or a polyphosphate ester). These epoxy resins may be used alone or in combination of two or more.

Among the epoxy resins, from the viewpoint of reactivity, it is preferable to have a glycidyl-type epoxy resin having a glycidyl group, and in particular, it is preferable to contain one or more of a polyglycidyl ether compound of a polynuclear polyhydric phenol compound, an epoxy compound having a glycidylamino group, and a polyglycidyl ether compound of dicyclopentadiene dimethanol (specifically, a diglycidyl ether compound). The inclusion of a polyglycidyl ether compound of a polynuclear polyhydric phenol compound is preferable in terms of heat resistance. The inclusion of an epoxy compound having a glycidylamino group is preferable in terms of both excellent reactivity and excellent heat resistance. The inclusion of a polyglycidyl ether compound of dicyclopentadiene dimethanol is preferable in terms of the effect of imparting adhesion.
In this specification, the term "glycidylamino group" may be monofunctional or bifunctional, but preferably refers to the difunctional "diglycidylamino group." All of the preferred numerical ranges of the amount of the "epoxy compound having a glycidylamino group" in this specification can be considered to be preferred numerical ranges of the amount of the "epoxy compound having a diglycidylamino group."

The number of epoxy groups in the epoxy resin (component (B)) per molecule is preferably 1.1 or more and 10 or less, as this provides excellent heat resistance and one-component stability, and more preferably 2 or more and 4 or less.

From the standpoint of heat resistance, it is preferable that the epoxy equivalent (g/eq) of the epoxy resin (component (B)) be 50 or more, more preferably 60 or more and 30,000 or less, and even more preferably 70 or more and 20,000 or less.

The epoxy resin as component (B) preferably has a molecular weight of 150 or more and 80,000 or less in terms of heat resistance, and more preferably 200 or more and 10,000 or less. When the epoxy resin is a polymer, the molecular weight can be measured as a weight average molecular weight, and can be measured by the following method.
The weight average molecular weight can be determined, for example, by GPC (gel permeation chromatography) measurement as a value converted into standard polystyrene, and can be measured, for example, under the following conditions.
The weight average molecular weight can be measured, for example, using a GPC (LC-2000plus series) manufactured by JASCO Corporation, using tetrahydrofuran as the elution solvent, polystyrene standards for the calibration curve with Mw of 1,110,000, 707,000, 397,000, 189,000, 98,900, 37,200, 13,700, 9,490, 5,430, 3,120, 1,010, and 589 (TSKgel standard polystyrene manufactured by Tosoh Corporation), and using KF-804, KF-803, and KF-802 (manufactured by Showa Denko K.K.) as measurement columns. The measurement temperature can be 40°C, and the flow rate can be 1.0 mL/min.

The amount of epoxy resin (component (B)) used is preferably 1 to 1,000 parts by mass, more preferably 3 to 500 parts by mass, and even more preferably 5 to 200 parts by mass, per 100 parts by mass of cyanate ester resin (component (A)), as this results in excellent cured product properties.

In the present invention, when an epoxy compound having a glycidyl group is contained as component (B), the content ratio of the compound relative to 100 parts by mass of the epoxy resin (B) is preferably 80 parts by mass or more and 100 parts by mass or less, and more preferably 95 parts by mass or more and 100 parts by mass or less.

In the present invention, when a polyglycidyl ether compound of a polynuclear polyhydric phenol compound is contained as component (B), the content ratio of the compound per 100 parts by mass of the epoxy resin (B) is preferably 10 parts by mass or more and 90 parts by mass or less, and more preferably 20 parts by mass or more and 80 parts by mass or less.

In the present invention, when an epoxy compound having a glycidylamino group is contained as component (B), the content of the compound relative to 100 parts by mass of the epoxy resin (B) is preferably 5 parts by mass or more, more preferably 10 parts by mass or more and 80 parts by mass or less, and particularly preferably 20 parts by mass or more and 80 parts by mass or less.

In the present invention, when a polyglycidyl ether compound of dicyclopentadiene dimethanol is contained as component (B), the content of the compound relative to 100 parts by mass of the epoxy resin (B) is preferably 5 parts by mass or more, more preferably 10 parts by mass or more and 80 parts by mass or less, and more preferably 15 parts by mass or more and 80 parts by mass or less.

In the present invention, by using an amine-based latent curing agent having active hydrogen as the curing agent, the effect of excellent reactivity and one-component stability is achieved.
Examples of the amine-based latent curing agent having active hydrogen, which is the component (C) used in the present invention, include dibasic acid dihydrazides such as oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, suberic acid dihydrazide, azelaic acid dihydrazide, sebacic acid dihydrazide, and phthalic acid dihydrazide; guanidine compounds such as dicyandiamide, benzoguanamine, and acetoguanamine; melamine; and modified amines such as dehydration condensates of amine and carboxylic acid, adducts of amine and epoxy, adducts of amine and isocyanate, Michael adducts of amine, Mannich reaction products of amine, condensates of amine and urea, and condensates of amine and ketone.

Among the amine-based latent curing agents having active hydrogens, preferred examples include guanidine compounds such as dicyandiamide, benzoguanamine, and acetoguanamine; or (C-1) modified amines obtained by reacting an amine compound having one or more active hydrogens with an epoxy compound, (C-2) modified amines obtained by reacting an amine compound having one or more active hydrogens with an isocyanate compound, (C-3) modified amines obtained by reacting an amine compound having one or more active hydrogens with an epoxy compound and an isocyanate compound, and (C-4) latent curing agents containing a phenolic resin in addition to at least one modified amine selected from (C-1), (C-2), or (C-3).

Examples of the amine compound having one or more active hydrogens include alkylenediamines such as ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,3-diaminobutane, 1,4-diaminobutane, and hexamethylenediamine; polyalkylpolyamines such as diethylenetriamine, triethylenetriamine, and tetraethylenepentamine; 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, 1,3-diaminomethylcyclohexane, 1,2-diaminocyclohexane, 1,4-diamino-3,6-diethylcyclohexane, 4,4'-diaminodicyclohexylmethane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 4,4'-diaminodicyclohexylpropane, bis(4-aminocyclohexyl)sulfone, and 4,4'-diaminodicyclohexyl ether. alicyclic polyamines such as m-xylylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, diethyltoluenediamine, 1-methyl-3,5-diethyl-2,4-diaminebenzene, 1-methyl-3,5-diethyl-2,6-diaminobenzene, 1,3,5-triethyl-2,6-diaminobenzene, 1,3,5-triethyl-2,6-diaminobenzene, 1,3,5-triethyl-2,6-diaminobenzene, 1,3,5-triethyl-2,6-diaminodiamine, 1,3,5-trimethyl-2,6-diaminodiamine ... aromatic polyamines such as benzoguanamine and acetoguanamine; 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-isopropylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole; imidazoles such as 2-aminopropylimidazole, 2-phenyl-4-methylimidazole, and 2-aminopropylimidazole; dihydrazides such as oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, suberic acid dihydrazide, azelaic acid dihydrazide, sebacic acid dihydrazide, and phthalic acid dihydrazide; N,N-dimethylaminoethylamine, N,N-diethylamino Ethylamine, N,N-diisopropylaminoethylamine, N,N-diallylaminoethylamine, N,N-benzylmethylaminoethylamine, N,N-dibenzylaminoethylamine, N,N-cyclohexylmethylaminoethylamine, N,N-dicyclohexylaminoethylamine, N-(2-aminoethyl)pyrrolidine, N-(2-aminoethyl)piperidine, N-(2-aminoethyl)morpholine, N-(2- N-(3-aminopropyl)piperazine, N-(2-aminoethyl)-N'-methylpiperazine, N,N-dimethylaminopropylamine, N,N-diethylaminopropylamine, N,N-diisopropylaminopropylamine, N,N-diallylaminopropylamine, N,N-benzylmethylaminopropylamine, N,N-dibenzylaminopropylamine, N,N-cyclohexylmethylaminopropylamine, N,N-dicyclohexylaminopropylamine, N-(3-aminopropyl)pyrrolidine, N-(3-aminopropyl)piperidine, N-(3-aminopropyl)morpholine, N-(3-aminopropyl)piperazine, N-(3-aminopropyl)-N'-methylpiperidine, 4-(N,N-dimethylamino)benzylamine, 4-(N,N-diethylamino)benzylamine, 4-(N,N-diisopropylamino)benzylamine, N, N- dimethylisophoronediamine, N,N-dimethylbisaminocyclohexane, N,N,N'-trimethylethylenediamine, N'-ethyl-N,N-dimethylethylenediamine, N,N,N'-trimethylethylenediamine, N'-ethyl-N,N-dimethylpropanediamine, N'-ethyl-N,N-dibenzylaminopropylamine; N,N-(bisaminopropyl)-N-methylamine, N,N-bisaminopropylethylamine, N,N-bisaminopropylpropylamine, N,N-bisaminopropylbutylamine, N,N-bis Examples thereof include aminopropylpentylamine, N,N-bisaminopropylhexylamine, N,N-bisaminopropyl-2-ethylhexylamine, N,N-bisaminopropylcyclohexylamine, N,N-bisaminopropylbenzylamine, N,N-bisaminopropylallylamine, bis[3-(N,N-dimethylaminopropyl)]amine, bis[3-(N,N-diethylaminopropyl)]amine, bis[3-(N,N-diisopropylaminopropyl)]amine, and bis[3-(N,N-dibutylaminopropyl)]amine.

The active hydrogen equivalent (g/eq) of the amine compound is preferably 10 or more and 300 or less, and more preferably 15 or more and 150 or less, in terms of the balance between curability and storage stability.

Examples of the epoxy compounds include polyglycidyl ether compounds of mononuclear polyhydric phenol compounds such as hydroquinone, resorcinol, pyrocatechol, and phloroglucinol; dihydroxynaphthalene, biphenol, methylene bisphenol (bisphenol F), methylene bis(ortho-cresol), ethylidene bisphenol, isopropylidene bisphenol (bisphenol A), isopropylidene bis(ortho-cresol), tetrabromobisphenol A, 1,3-bis(4-hydroxycumylbenzene), 1,4-bis(4-hydroxycumylbenzene), 1,1,3-tris(4-hydroxyphenyl)butane, and 1 Polyglycidyl ether compounds of polynuclear polyhydric phenol compounds such as 1,2,2-tetra(4-hydroxyphenyl)ethane, thiobisphenol, sulfonylbisphenol, oxybisphenol, phenol novolac, orthocresol novolac, ethylphenol novolac, butylphenol novolac, octylphenol novolac, resorcinol novolac, and terpene phenol; ethylene glycol, propylene glycol, butylene glycol, hexanediol, polyglycol, thiodiglycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, bisphenol A-alkylene olefin polyglycidyl ethers of polyhydric alcohols such as oxide adducts; glycidyl esters of aliphatic, aromatic or alicyclic polybasic acids such as maleic acid, fumaric acid, itaconic acid, succinic acid, glutaric acid, suberic acid, adipic acid, azelaic acid, sebacic acid, dimer acid, trimer acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, trimesic acid, pyromellitic acid, tetrahydrophthalic acid, hexahydrophthalic acid, and endomethylenetetrahydrophthalic acid, and homopolymers or copolymers of glycidyl methacrylate; N,N-diglycidylaniline, bis(4-(N-methyl-N-glycidylamino)phenyl)methane, diglycidyl Examples of the epoxy compound include an epoxy compound having a glycidylamino group such as orthotoluidine; an epoxidized product of a cyclic olefin compound such as vinylcyclohexene diepoxide, dicyclopentadiene diepoxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl-6-methylcyclohexanecarboxylate, and bis(3,4-epoxy-6-methylcyclohexylmethyl)adipate; an epoxidized conjugated diene polymer such as epoxidized polybutadiene and epoxidized styrene-butadiene copolymer; and a heterocyclic compound such as triglycidyl isocyanurate.

The epoxy compound may be either a glycidyl-type epoxy compound, which is an epoxy compound having a glycidyl group, or a cycloalkene oxide-type epoxy compound, such as an epoxidized product of a cyclic olefin compound. Furthermore, if the epoxy compound is a glycidyl-type, it may be either an aromatic epoxy compound having an aromatic ring or an aliphatic epoxy compound not having an aromatic ring. From the standpoint of reactivity, it is preferable to use a glycidyl-type epoxy compound as the epoxy compound, and from the standpoint of heat resistance, it is even more preferable to use a glycidyl-type aromatic epoxy compound.

Examples of the isocyanate compound include aromatic diisocyanates such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, diphenylmethane-4,4'-diisocyanate, phenylene diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, 1,5-naphthylene diisocyanate, 1,5-tetrahydronaphthalene diisocyanate, 3,3'-dimethyldiphenyl-4,4'-diisocyanate, dianisidine diisocyanate, and tetramethylxylylene diisocyanate; isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate; Aliphatic diisocyanates such as tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 2,2,4 and/or (2,4,4)-trimethylhexamethylene diisocyanate, lysine diisocyanate, etc.; isocyanurate trimer, biuret trimer, trimethylolpropane adduct of the above-exemplified diisocyanates, etc.; triphenylmethane triisocyanate, 1-methylbenzene-2,4,6-triisocyanate, dimethyltriphenylmethane tetraisocyanate, etc.
Furthermore, these isocyanate compounds may be used in a carbodiimide-modified, isocyanurate-modified, biuret-modified or other form, or may be used in the form of a blocked isocyanate blocked with various blocking agents.

In the modified amine (C-1), the amine compound having one or more active hydrogens and the epoxy compound are preferably used in such amounts that the epoxy group of the epoxy compound is 0.1 to 0.9 equivalents, particularly 0.2 to 0.8 equivalents, per equivalent of active hydrogen of the amine compound.
In the modified amine (C-2), the amine compound having one or more active hydrogens and the isocyanate compound are preferably used in such amounts that the isocyanate group of the isocyanate compound is 0.1 to 0.9 equivalents, particularly 0.2 to 0.8 equivalents, per equivalent of active hydrogen of the amine compound.
Furthermore, in the modified amine (C-3), the amounts of the amine compound having one or more active hydrogens , the epoxy compound , and the isocyanate compound are preferably such that the total amount of epoxy groups of the epoxy compound and isocyanate groups of the polyisocyanate compound is 0.1 to 0.9 equivalents, particularly 0.2 to 0.8 equivalents, per equivalent of active hydrogen of the amine compound.
Here, by setting the amount of the epoxy compound and/or the isocyanate compound relative to the amine compound having one or more active hydrogens to the above lower limit or more, the storage stability of the curable resin composition can be improved, which is preferable, and by setting it to the above upper limit or less, curability can be reliably obtained, which is preferable.

The method for producing the modified amines (C-1), (C-2), and (C-3) is not particularly limited, but examples thereof include a method in which a solvent is used as needed, and the reaction is carried out under heating at room temperature to 140°C for 1 to 10 hours.
In the case of the modified amine (C-3), it is usually preferred to react an amine compound with an epoxy compound and then react the polyisocyanate compound with the amine compound. When a solvent is used, the solvent can be removed after the reaction is completed by heating under normal pressure or reduced pressure.

The solvents used in producing the modified amine include ketones such as methyl ethyl ketone, methyl amyl ketone, diethyl ketone, acetone, methyl isopropyl ketone, propylene glycol monomethyl ether acetate, and cyclohexane; ethers such as tetrahydrofuran, 1,2-dimethoxyethane, 1,2-diethoxyethane, and propylene glycol monomethyl ether; esters such as ethyl acetate and n-butyl acetate; aromatic hydrocarbons such as benzene, toluene, and xylene; halogenated aliphatic hydrocarbons such as carbon tetrachloride, chloroform, trichloroethylene, and methylene chloride; and halogenated aromatic hydrocarbons such as chlorobenzene.

Examples of phenolic resins used in component (C-4) include polyhydric phenol compounds such as phenol novolac resins, cresol novolac resins, aromatic hydrocarbon formaldehyde resin-modified phenolic resins, dicyclopentadiene phenol adduct resins, phenol aralkyl resins (Xyloc resins), naphthol aralkyl resins, trisphenylolmethane resins, tetraphenylolethane resins, naphthol novolac resins, naphthol-phenol co-condensed novolac resins, naphthol-cresol co-condensed novolac resins, biphenyl-modified phenolic resins (polyhydric phenol compounds in which phenol nuclei are linked by bismethylene groups), biphenyl-modified naphthol resins (polyhydric naphthol compounds in which phenol nuclei are linked by bismethylene groups), aminotriazine-modified phenolic resins (compounds having a phenol skeleton, a triazine ring, and a primary amino group in their molecular structure), and alkoxy group-containing aromatic ring-modified novolac resins (polyhydric phenol compounds in which phenol nuclei and alkoxy group-containing aromatic rings are linked by formaldehyde).

In the present invention, in order to obtain a curable resin composition with an excellent balance between storage stability and curability, it is preferable to use a (C-4) phenolic resin having a softening point of 50 to 200°C.

The amount of phenolic resin used in (C-4) is preferably 10 to 100 parts by mass, and particularly preferably 20 to 60 parts by mass, per 100 parts by mass of the modified amines (components (C-1), (C-2), and (C-3)). An amount of 10 parts by mass or more ensures sufficient curability, while an amount of 100 parts by mass or less more reliably avoids a decrease in the physical properties of the cured product, which is preferred.

Furthermore, the latent curing agents (C-1) to (C-4) may be used after being pulverized using a pulverizer such as a jet mill.

Among the (C) amine-based latent curing agents having active hydrogen, commercially available products include ADEKA HARDNER EH-3636AS (manufactured by ADEKA Corporation; dicyandiamide-type latent curing agent), ADEKA HARDNER EH-4351S (manufactured by ADEKA Corporation; dicyandiamide-type latent curing agent), ADEKA HARDNER EH-5011S (manufactured by ADEKA Corporation; imidazole-type latent curing agent), ADEKA HARDNER EH-5046S (manufactured by ADEKA Corporation; imidazole-type latent curing agent), ADEKA HARDNER EH-4357S (manufactured by ADEKA Corporation; polyamine-type latent curing agent), ADEKA HARDNER EH-5057P (manufactured by ADEKA Corporation; polyamine-type latent curing agent), and ADEKA HARDNER Examples of such curing agents include EH-5057PK (manufactured by ADEKA Corporation; polyamine-type latent curing agent), Amicure PN-23 (manufactured by Ajinomoto Fine-Techno Co., Ltd.; amine adduct-based latent curing agent), Amicure PN-40 (manufactured by Ajinomoto Fine-Techno Co., Ltd.; amine adduct-based latent curing agent), Amicure VDH (manufactured by Ajinomoto Fine-Techno Co., Ltd.; hydrazide-based latent curing agent), and Fujicure FXR-1020 (manufactured by T&K TOKA Corporation; latent curing agent).

The amount of the (C) amine-based latent curing agent having active hydrogen used is not particularly limited, but for reasons of reactivity and one-component stability, it is preferably 1 to 70 parts by mass, and more preferably 3 to 60 parts by mass, per 100 parts by mass of the total amount of (A) cyanate ester resin and (B) epoxy resin.

In the present invention, known curing accelerators can be used in combination with the (C) active hydrogen-containing amine-based latent curing agent, as needed. Specific examples of these curing accelerators include phosphines such as triphenylphosphine; phosphonium salts such as tetraphenylphosphonium bromide; imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, and 1-cyanoethyl-2-methylimidazole; imidazole salts formed from the above imidazoles with trimellitic acid, isocyanuric acid, boron, or the like; benzyldimethylamine, 2,4,6-tris(trimethylsilyl)amine, and the like. Examples of the curing accelerator include amines such as (dimethylaminomethyl)phenol; quaternary ammonium salts such as tetramethylammonium chloride; ureas such as 3-(p-chlorophenyl)-1,1-dimethylurea, 3-(3,4-dichlorophenyl)-1,1-dimethylurea, 3-phenyl-1,1-dimethylurea, isophorone diisocyanate-dimethylurea, and tolylene diisocyanate-dimethylurea; and complex compounds of boron trifluoride with amines, ether compounds, and the like. These curing accelerators may be used alone or in combination of two or more. The content of the curing accelerator in the curable resin composition of the present invention is not particularly limited and can be set appropriately depending on the application of the curable resin composition.

The ion scavenger (component (D)) used in the present invention preferably has an ion exchange capacity of 1.0 meq/g or more, since this provides excellent anti-fogging properties under high temperature and high humidity conditions. The upper limit of the ion exchange capacity is usually 10 meq/g or less.
The ion exchange capacity of the ion trapping agent is measured by ICP emission spectrometry, for example, the following method described in the pamphlet of WO2008/053694.
1.0 g of a test sample and 50 mL of a 0.1 mol/L aqueous sodium hydroxide solution are placed in a 100 mL polyethylene bottle and shaken at 40°C for 20 hours, after which the sodium ion concentration of the supernatant is measured using an ICP atomic emission spectrometer. The sodium ion concentration is measured in the same manner without the sample, and this is used as the blank value to calculate the ion exchange capacity.
The ion scavenger used in the present invention preferably has at least a cation-scavenging ability, and more preferably has both ion-scavenging ability and cation-scavenging ability.

The ion scavenger, component (D) used in the present invention, is a material with ion-trapping ability that can capture decomposition components generated from the curable resin composition when exposed to a high-temperature, high-humidity environment. It can be organic or inorganic, but inorganic ion scavengers are preferred from the perspective of their excellent heat resistance. Inorganic fine particles with ion-trapping ability are particularly preferred because they have excellent heat resistance and are easily dispersed uniformly in the curable resin composition.

The inorganic fine particles having ion-trapping ability are preferably inorganic fine particles containing at least one metal element selected from zirconium, antimony, bismuth, aluminum, magnesium, yttrium, lanthanum, and neodymium, in particular, from the viewpoint of excellent ability to trap decomposed substances derived from glass under high temperature and high humidity. The composition of the inorganic fine particles containing a metal element may be either a simple metal or a metal compound, but a metal compound is preferred in terms of excellent ability to trap decomposed substances derived from glass under high temperature and high humidity. Specific examples of the composition of inorganic fine particles having ion-trapping ability include zirconium phosphate, zirconium tungstate, zirconium molybdate, zirconium tungstate, zirconium antimonate, zirconium selenate, zirconium tellurite, zirconium silicate, zirconium phosphosilicate, zirconium polyphosphate, bismuth oxide compounds, bismuth hydroxide compounds, yttrium oxide, lanthanum oxide, neodymium oxide, composite oxides of magnesium and aluminum, hydrotalcite, hydrocalumite, hydroohmite, zeolite, other metal composite compounds, and mixtures thereof. These may be natural or artificial.
The particle size of these ion trapping agents is preferably 0.001 to 100 μm, particularly 0.01 to 20 μm, from the viewpoint of excellent trapping ability of glass-derived decomposition products under high temperature and high humidity conditions. The particle size referred to here is an average particle size, which can be measured by a laser diffraction/scattering method. Specifically, a particle size distribution of the inorganic ion trapping agent is prepared on a volume basis using a laser diffraction/scattering particle size distribution measuring device, and the median diameter thereof can be used as the above-mentioned particle size (average particle size).

Among the above-mentioned ion scavengers, inorganic fine particles containing magnesium, aluminum, and zirconium are preferred because of their excellent anti-fogging effect. Of these, ion scavengers that are fine particles containing magnesium, aluminum, and zirconium and have a particle size (median size) of 0.01 to 10 μm are more preferred. Among these, those that do not contain bismuth are particularly preferred because of their excellent anti-fogging effect.

Examples of commercially available ion scavengers include IXE-100, IXE-300, IXE-500, IXE-530, IXE-550, IXE-600, IXE-633, IXE-700F, IXE-770D, IXE-800, IXE-1000, IXE-6107, IXE-6136, IXEPLAS-A1, IXEPLAS-A2, and IXEPLAS-B1 (manufactured by Toagosei Co., Ltd.); Kyoward 200, Kyoward 500, Kyoward 600, Kyoward 700, KW-2000, and DHT-4A (manufactured by Kyowa Chemical Industry Co., Ltd.).
Examples of particularly preferred commercially available ion scavengers include IXEPLAS-A1 and A2.

The amount of the ion scavenger (component (D)) used in the present invention is preferably 0.01 to 5 parts by mass, more preferably 0.1 to 5 parts by mass, particularly preferably 1 to 5 parts by mass, and most preferably 1.5 to 5 parts by mass, based on 100 parts by mass of the total amount of components (A), (B), and (C). An amount of 0.01 parts by mass or more can prevent the risk of not achieving the anti-fogging improvement effect, while an amount of 10 parts by mass or less can prevent the risk of adversely affecting the physical properties of the cured resin composition.

The curable resin composition of the present invention may further contain a phosphorus-based antioxidant, a phenol-based antioxidant, or a sulfur-based antioxidant.

Examples of the phosphorus-based antioxidants include triphenyl phosphite, tris(2,4-di-tert-butylphenyl) phosphite, tris(nonylphenyl) phosphite, tris(dinonylphenyl) phosphite, tris(mono- and di-mixed nonylphenyl) phosphite, bis(2-tert-butyl-4,6-dimethylphenyl) ethyl phosphite, diphenyl acid phosphite, 2,2'-methylenebis(4,6-di-tert-butylphenyl)octyl phosphite, diphenyl decyl phosphite, and phenyl diisopropyl phosphate. Decyl phosphite, tributyl phosphite, tris(2-ethylhexyl) phosphite, tridecyl phosphite, trilauryl phosphite, dibutyl acid phosphite, dilauryl acid phosphite, trilauryl trithiophosphite, bis(neopentyl glycol)-1,4-cyclohexanedimethyl diphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, di Stearyl pentaerythritol diphosphite, phenyl-4,4'-isopropylidenediphenol pentaerythritol diphosphite, tetra(C12-15 mixed alkyl)-4,4'-isopropylidenediphenyl phosphite, bis[2,2'-methylenebis(4,6-diamylphenyl)]isopropylidenediphenyl phosphite, hydrogenated-4,4'-isopropylidenediphenol polyphosphite, bis(octylphenyl)bis[4,4'-n-butylidenebis(2-tert-butyl-5-methyl [0039] tetratridecyl-4,4'-butylidenebis(2-tert-butyl-5-methylphenol) diphosphite, hexa(tridecyl)-1,1,3-tris(2-methyl-5-tert-butyl-4-hydroxyphenyl)butane triphosphonite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2-butyl-2-ethylpropanediol-2,4,6-tri-tert-butylphenol monophosphite, and the like.

Examples of the phenolic antioxidants include 2,6-di-tert-butyl-p-cresol, 2,6-diphenyl-4-octadecyloxyphenol, stearyl (3,5-di-tert-butyl-4-hydroxyphenyl)propionate, distearyl (3,5-di-tert-butyl-4-hydroxybenzyl)phosphonate, tridecyl 3,5-di-tert-butyl-4-hydroxybenzylthioacetate, thiodiethylenebis[(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], and 4,4'-thiobis(6-tert-butyl-m-cresol). ), 2-octylthio-4,6-di(3,5-di-tert-butyl-4-hydroxyphenoxy)-s-triazine, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), bis[3,3-bis(4-hydroxy-3-tert-butylphenyl)butylic acid]glycol ester, 4,4'-butylidenebis(4,6-di-tert-butylphenol), 2,2'-ethylidenebis(4,6-di-tert-butylphenol), 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, bis[2-tert-butyl-4- methyl-6-(2-hydroxy-3-tert-butyl-5-methylbenzyl)phenyl] terephthalate, 1,3,5-tris(2,6-dimethyl-3-hydroxy-4-tert-butylbenzyl) isocyanurate, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene, 1,3,5-tris[(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxyethyl] isocyanurate, tetramethylbenzyl Examples of suitable bis[methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]methane, 2-tert-butyl-4-methyl-6-(2-acryloyloxy-3-tert-butyl-5-methylbenzyl)phenol, 3,9-bis[2-(3-tert-butyl-4-hydroxy-5-methylhydrocinnamoyloxy)-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane], triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate], and the like.

Examples of the sulfur-based antioxidant include dialkyl thiodipropionates such as dilauryl, dimyristyl, myristylstearyl, and distearyl esters of thiodipropionic acid, and β-alkyl mercaptopropionic acid esters of polyols such as pentaerythritol tetra(β-dodecylmercaptopropionate).

The curable resin composition of the present invention may also contain an ultraviolet absorber or a hindered amine-based light stabilizer.

Examples of the ultraviolet absorber include 2-hydroxybenzophenones such as 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-tert-butyl-4'-(2-methacryloyloxyethoxyethoxy)benzophenone, and 5,5'-methylenebis(2-hydroxy-4-methoxybenzophenone); 2-(2-hydroxy-5-methylphenyl)benzotriazole, 2-(2-hydroxy-5-tert-octylphenyl)benzotriazole, and 2-(2-hydroxy-3,5 2-(2-hydroxy-3-tert-butyl-5-methylphenyl)-5-chlorobenzotriazole, 2-(2-hydroxy-3-dodecyl-5-methylphenyl)benzotriazole, 2-(2-hydroxy-3-tert-butyl-5-C7-9 mixed alkoxycarbonylethylphenyl)triazole, 2-(2-hydroxy-3,5-dicumylphenyl)benzotriazole, 2,2'-methylenebis(4-tert-octyl-6-benzotriazolylphenol), 2-(2-hydroxy-3-tert-butyl-5-carboxyphenyl)benzotriazole, 2-(2-hydroxyphenyl)benzotriazoles such as polyethylene glycol esters of 2-(2-hydroxyphenyl)benzotriazole; 2-(2-hydroxyphenyl)-1,3,5-triazine such as 2-(2-hydroxy-4-hexyloxyphenyl)-4,6-diphenyl-1,3,5-triazine, 2-(2-hydroxy-4-methoxyphenyl)-4,6-diphenyl-1,3,5-triazine, and 2-(2-hydroxy-4-octoxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine; phenyl salicylate, resorcinol monobenzyl ester, and the like. benzoates such as 2-ethyl-2'-ethoxyoxanilide and 2-ethoxy-4'-dodecyloxanilide; and cyanoacrylates such as ethyl-α-cyano-β,β-diphenylacrylate and methyl-2-cyano-3-methyl-3-(p-methoxyphenyl)acrylate.

Examples of the hindered amine light stabilizer include 2,2,6,6-tetramethyl-4-piperidyl stearate, 1,2,2,6,6-pentamethyl-4-piperidyl stearate, 2,2,6,6-tetramethyl-4-piperidyl benzoate, bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate, tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate, tetrakis(1,2,2,6,6-pentamethyl-4-piperidyl)-1, 2,3,4-butanetetracarboxylate, bis(2,2,6,6-tetramethyl-4-piperidyl)bis(tridecyl)-1,2,3,4-butanetetracarboxylate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)bis(tridecyl)-1,2,3,4-butanetetracarboxylate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)-2-butyl-2-(3,5-di-tert-butyl-4-hydroxybenzyl)malonate, 1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-piperidinol/diethyl succinate polycondensate, 1,6 -bis(2,2,6,6-tetramethyl-4-piperidylamino)hexane/dibromoethane polycondensate, 1,6-bis(2,2,6,6-tetramethyl-4-piperidylamino)hexane/2,4-dichloro-6-morpholino-s-triazine polycondensate, 1,6-bis(2,2,6,6-tetramethyl-4-piperidylamino)hexane/2,4-dichloro-6-tert-octylamino-s-triazine polycondensate, 1,5,8,12-tetrakis[2,4-bis(N-butyl-N-(2,2,6,6-tetramethyl-4-piperidyl)amino)-s-triazin-6-yl]-1,5,8,12 -tetraazadodecane, 1,5,8,12-tetrakis[2,4-bis(N-butyl-N-(1,2,2,6,6-pentamethyl-4-piperidyl)amino)-s-triazin-6-yl]-1,5,8,12-tetraazadodecane, 1,6,11-tris[2,4-bis(N-butyl-N-(2,2,6,6-tetramethyl-4-piperidyl)amino-s-triazin-6-ylamino]undecane, 1,6,11-tris[2,4-bis(N-butyl-N-(1,2,2,6,6-pentamethyl-4-piperidyl)amino-s-triazin-6-ylamino]undecane, and the like.

The curable resin composition of the present invention may contain a silane coupling agent. Examples of the silane coupling agent include γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-N'-β-(aminoethyl)-γ-aminopropyltriethoxysilane, γ-anilinopropyltriethoxysilane, γ-glycidoxypropyltriethoxysilane, β-(3,4-epoxycyclohexyl)ethyltriethoxysilane, vinyltriethoxysilane, N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, and γ-glycidoxypropyltrimethoxysilane.

The curable resin composition of the present invention can contain a filler. Examples of the filler include silica such as fused silica and crystalline silica; powders such as magnesium hydroxide, aluminum hydroxide, zinc molybdate, calcium carbonate, silicon carbonate, calcium silicate, potassium titanate, beryllia, zirconia, zircon, fosterite, steatite, spinel, mullite, and titania, or spherical beads thereof, and inorganic fillers such as glass fiber, pulp fiber, synthetic fiber, and ceramic fiber; organic fillers such as acrylic resin, silicone resin, polystyrene resin, and polydivinylbenzene; rubber fillers such as acrylonitrile-butadiene rubber (NBR) and styrene-butadiene rubber (SBR); and core-shell rubber fillers having a core made of butadiene rubber or the like and a shell made of acrylic resin, epoxy resin, or the like.
Examples of commercially available fillers include the Metablen (registered trademark) E series, Metablen (registered trademark) C series, and Metablen (registered trademark) W series manufactured by Mitsubishi Rayon Co., Ltd.; the MX series, SX series, and SGP series manufactured by Soken Chemical & Engineering Co., Ltd.; the Zefiac series manufactured by Aica Kogyo Co., Ltd.; the ChromoSphere-T series manufactured by ThermoFisherScientific; the Estapor (registered trademark) series manufactured by MerckChimie; Finepearl (registered trademark) manufactured by Matsuura Co., Ltd.; XER-91P and XER-81P manufactured by JSR Corporation; and TMS-2670 manufactured by The Dow Chemical Company.

When the curable resin composition of the present invention contains a filler, the content of the filler is preferably 20 to 1,000 parts by mass per 100 parts by mass of the total amount of (A) cyanate ester resin, (B) epoxy resin, and (C) active hydrogen-containing amine-based latent curing agent, from the viewpoint of workability when made into a one-component composition, and more preferably 50 to 500 parts by mass.

The curable resin composition of the present invention can be dissolved in various solvents, preferably organic solvents, before use. Suitable organic solvents include, for example, ethers such as tetrahydrofuran, 1,2-dimethoxyethane, and 1,2-diethoxyethane; alcohols such as iso- or n-butanol, iso- or n-propanol, amyl alcohol, benzyl alcohol, furfuryl alcohol, and tetrahydrofurfuryl alcohol; ketones such as methyl ethyl ketone, methyl isopropyl ketone, and methyl butyl ketone; aromatic hydrocarbons such as benzene, toluene, and xylene; triethylamine, pyridine, dioxane, and acetonitrile.

The curable resin composition of the present invention may further contain various other additives as needed. Examples of such additives include phenolic compounds such as biphenol; reactive diluents such as monoalkyl glycidyl ether; non-reactive diluents (plasticizers) such as dioctyl phthalate, dibutyl phthalate, benzyl alcohol, and coal tar; reinforcing materials such as glass cloth, aramid cloth, and carbon fiber; pigments; lubricants such as candelilla wax, carnauba wax, Japan wax, Ibota wax, beeswax, lanolin, spermaceti, montan wax, petroleum wax, aliphatic wax, aliphatic esters, aliphatic ethers, aromatic esters, and aromatic ethers; thickeners; thixotropic agents; antifoaming agents; rust inhibitors; and commonly used additives such as colloidal silica, colloidal alumina, carbon black, titanium black, benzimidazolidinone, and dicyclohexylurea. The present invention may also include adhesive resins such as xylene resins and petroleum resins.

In the curable resin composition of the present invention, the amount of components other than (A) cyanate ester resin, (B) epoxy resin, (C) amine-based latent curing agent having active hydrogen, and (D) ion scavenger (excluding fillers and solvents) may be any amount that does not impair curability and anti-fogging properties, but is preferably 10% by mass or less of the solid content of the composition in order to ensure sufficient amounts of (A) to (D), and more preferably 5% by mass or less.

When the curable resin composition of the present invention is cured, it is preferably heated at, for example, 80 to 200° C., in order to exhibit the physical properties of the cured product.
The curable resin composition of the present invention is useful as a one-component curable resin composition that is cured by heating.

The curable resin composition of the present invention can be used as a coating or adhesive for concrete, cement mortar, various metals, leather, glass, rubber, plastic, wood, cloth, paper, etc. In particular, because it has excellent fast-curing properties, heat resistance, and anti-fogging properties, it is ideally suited for use as a coating or adhesive for optical materials.

In the present invention, even when the cured product is left at high temperatures, for example, 50 to 100°C and relative humidity of 0 to 90%, particularly at high temperatures and high humidity for long periods of time, for example, 500 hours or more, it can effectively prevent fogging of optical elements and components such as lenses, mirrors, prisms, filters, and fibers, solar cell components such as solar panels, and display components such as liquid crystal panels and touch panels.

Next, the present invention will be explained in more detail using examples and comparative examples, but the present invention is not limited to these examples in any way.

Production Example 1 (Synthesis of modified polyamine)
A flask was charged with 201 g (2.71 mol) of 1,2-diaminopropane and heated to 60 ° C., followed by 580 g (3.05 equivalents) of ADEKA RESIN EP-4100E (trade name of ADEKA Corporation; bisphenol A type epoxy resin with an epoxy equivalent of 190). The temperature in the system was maintained at 100-110 ° C. After all of the ADEKA RESIN EP-4100E was added, the reaction system was heated to 140 ° C., and the reaction was continued for 1.5 hours to obtain a modified polyamine. Next, 30 g of MP-800K (manufactured by Asahi Organic Chemicals Co., Ltd.; phenolic resin, softening point 100 ° C.) was charged to 100 g of the resulting modified polyamine. The mixture was then degassed under reduced pressure at 180-190 ° C. and 30-40 Torr for 1 hour to remove unreacted material. The mixture was then pulverized using a jet mill to obtain a latent curing agent (EH-1).

[Examples 1 to 4 and Comparative Example 1]
Resin compositions were prepared by mixing the components according to the formulations shown in Table 1 below, and the following tests were carried out. The evaluation results are shown in Table 1 below. The numerical values for the formulations shown in Table 1 represent parts by mass. In addition, "ion scavenger to resin" in Table 1 indicates the mass ratio (mass %) of component (D) to the total amount of components (A) to (C).

<Curing degree>
The resin composition was placed in an aluminum pan and the total calorific value was measured by DSC. The resin composition was also placed in an aluminum pan and cured by heating in an oven set at 120°C for 1 hour, and the residual calorific value was measured by DSC. The degree of cure (%) was calculated using the following formula.
Degree of cure (%) = [(total heat generation amount - residual heat generation amount) / total heat generation amount] x 100

<Anti-fogging>
0.1 g of the resin composition was thinly spread in the center of a glass petri dish (outer diameter 75 mm x height 20 mm, made of ordinary glass) and heat-cured for 1 hour in an oven set to 120°C. The dish was covered with a lid leaving a gap of about 500 μm and placed in a thermo-hygrostat set to a temperature of 85°C and a relative humidity of 85% for 2000 hours. After the test was completed, the petri dish was removed and the glass surface around the cured product was observed with an optical microscope. The anti-fogging property was evaluated on a 4-point scale based on the time until fogging occurred.
D: Clouding occurs within 500 hours.
C: Almost no clouding was observed up to 500 hours, but clouding occurred by 1000 hours.
B: Almost no clouding was observed up to 1000 hours, but clouding occurred by 2000 hours.
A: Almost no clouding was observed up to 2000 hours.

EP-1: EP-4300E (bisphenol A type epoxy resin (polyglycidyl ether compound of polynuclear polyhydric phenol compound) manufactured by ADEKA Corporation)
EP-2: EP-3950S (aminophenol type epoxy resin (epoxy compound having a glycidylamino group)) manufactured by ADEKA Corporation
EP-3: EP-4088S (dicyclopentadiene type epoxy resin (dicyclopentadiene dimethanol polyglycidyl ether compound) manufactured by ADEKA Corporation)
CY-1: Lecy (bisphenol-type cyanate ester resin) manufactured by Lonza
Silica: 200SX-E1 manufactured by Admatechs Co., Ltd.
IC-1: IXEPLAS-A1 (Mg, Al, Zr-based ion scavenger, median diameter 0.5 μm, ion exchange capacity Na ⁺ 1 meq/g or more and 10 meq/g or less: catalog value) manufactured by Toagosei Co., Ltd.

As shown in the above examples, the curable resin composition of the present invention has excellent curing properties as no decrease in the degree of cure is observed, and the resulting cured product has excellent anti-fogging properties under high temperature and high humidity conditions.

The curable resin composition of the present invention is particularly excellent in curability and in the anti-fogging properties of the resulting cured product under high temperature and high humidity conditions, and therefore can be suitably used, for example, as an adhesive for optical components.

Claims (7)

A curable resin composition comprising (A) a cyanate ester resin, (B) an epoxy resin, (C) an amine -based latent curing agent having active hydrogen, and (D) an ion scavenger, wherein the amine-based latent curing agent having active hydrogen, which is component (C), is at least one selected from the following (C-1) to (C-4), and the ion scavenger, which is component (D), is inorganic fine particles containing at least one metal element selected from zirconium, antimony, bismuth, aluminum, magnesium, yttrium, lanthanum, and neodymium, and has an ion exchange capacity for Na ⁺ of 1.0 meq/g or more .
(C-1): A modified amine obtained by reacting an amine compound having one or more active hydrogen atoms with an epoxy compound.
(C-2): Modified amine obtained by reacting an amine compound having one or more active hydrogens with an isocyanate compound.
(C-3): Modified amine obtained by reacting an amine compound having one or more active hydrogen atoms, an epoxy compound, and an isocyanate compound.
(C-4): A latent curing agent containing at least one modified amine selected from (C-1), (C-2) and (C-3) and a phenolic resin. 2. The curable resin composition according to claim 1, wherein the cyanate ester resin (A) is at least one selected from the group consisting of a compound represented by the following formula (1), a compound represented by the following formula (2), and at least one polymer selected from these:

NC-O-A ¹ -Y ¹ -A ² -O-CN (1)

(In the formula, Y ¹ represents a divalent hydrocarbon group that is unsubstituted or substituted with a fluorine atom or a cyanato group, or represents —O—, —S—, or a single bond, and A ¹ and A ² each independently represent a phenylene group that is unsubstituted or substituted with 1 to 4 alkyl groups.)
(In the formula, m is an integer of 1 or greater; ^Y2 and ^Y3 each independently represent -S- or a divalent hydrocarbon group that is unsubstituted or substituted with a fluorine atom or a cyanato group; ^R1 , ^R2 , ^R3 , ^R4 , ^R5 , and ^R6 each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.) The curable resin composition according to claim 2, wherein Y ¹ in the formula (1) and Y ² and Y ³ in the formula (2) are each independently at least one selected from the following formulas (Y-1) to (Y-9):
Here, n is an integer of 4 to 12, ^R7 and ^R8 are each independently a hydrogen atom or an unsubstituted or fluorine-substituted methyl group, and * represents a bond. 2. The curable resin composition according to claim 1 , wherein the active hydrogen-containing amine-based latent curing agent of component (C) is a latent curing agent of component (C-4). 5. The curable resin composition according to claim 1, wherein the ion scavenger (D) is inorganic fine particles containing magnesium, aluminum, and zirconium. A cured product obtained by curing the curable resin composition according to any one of claims 1 to 5 . An adhesive comprising the curable resin composition according to any one of claims 1 to 5 .